https://github.com/shadow-maint/shadow/commit/d8e54618feea201987c1f3cb402ed50d1d8b604f

Index: shadow-4.9/src/pwck.c
===================================================================
--- shadow-4.9.orig/src/pwck.c
+++ shadow-4.9/src/pwck.c
@@ -857,6 +857,7 @@ int main (int argc, char **argv)
 	 * Get my name so that I can use it to report errors.
 	 */
 	Prog = Basename (argv[0]);
+	shadow_logfd = stderr;
 
 	(void) setlocale (LC_ALL, "");
 	(void) bindtextdomain (PACKAGE, LOCALEDIR);